U.S. Pat. No. 6,598,528 discloses a rotary printing press provided with a safety system. The safety system has a plurality of light-emitter units and a plurality of associated light-receiver units. These units create a light curtain which is used to check whether a human being enters into the space situated between the print unit during the operation of automatically changing plates.
Rotary printing presses are also known that are provided with respective devices for engaging the strip of paper in the press, enabling the strip to be engaged automatically between the cylinders of the print units.
Nevertheless, in such presses, when initiating strip engagement, in order to avoid accidents it is necessary to verify manually whether the path for the strip is free and that nobody is on that path.